A TRANSFUSION of blood from runners could be a ground-breaking treatment for slowing down Alzheimer's disease.
It's thought that a cocktail of chemicals released in the blood after exercise has rejuvenating and protective effects on the brain; previous research has found those who exercise regularly are less likely to develop the condition.
Now doctors are giving monthly transfusions to around 60 people with early signs of Alzheimer's in a year-long clinical trial led by the Norwegian University of Science and Technology.
Alzheimer's disease is the most common cause of dementia - around 850,000 people in the UK have some form of dementia, and with an ageing population this number is predicted to rise to 1.5 million within the next two decades.
The exact cause of Alzheimer's is not yet fully understood, although a number of factors are thought to increase your risk, including a family history and cardiovascular disease, as well as lifestyle factors such as obesity.
Meanwhile, a number of studies have shown that regular exercise and cardiac and respiratory fitness can lower the risk and the progression of the disease.
For instance, a study in 2019 by St Olav's Hospital in Norway - which is also part of the new trial - based on data from 30,000 people, revealed those who increased their lung capacity through exercise, had a 40 to 50 per cent reduced risk of having Alzheimer's more than 10 years later.
"Maintaining or improving cardiorespiratory fitness over time may be a target to reduce risk of dementia incidence and mortality, delay onset and increase longevity after diagnosis," the researchers wrote in the journal The Lancet Public Health.
One theory is that exercise causes complex chemical changes in the blood that affect the brain and counteract age-related and disease-related changes associated with Alzheimer's.
These chemical changes were identified in a study by Stanford University in the United States last year.
Researchers measured the blood levels of 17,662 molecules before and after 10 minutes of exercise, and found specific changes occurred in more than half of cases.
Some compounds increased, while others dropped. The molecules were involved in many different areas, from the immune system and appetite, to tissue repair and inflammation.
Doctors described the molecular changes following exercise as a "symphony" that could be beneficial in dementia, reported the journal Cell.
The idea behind the new treatment is that the same changes can be created in the brains of people with early-stage dementia through blood transfused from fit, young people who have exercised.
In the trial, patients aged from 50 to 75 with mild cognitive impairment or early Alzheimer's will be given monthly 200ml transfusions of blood for 12 months.
The blood will be taken from 30 volunteers aged 18 to 40, who will run on a treadmill to the point of exhaustion, before giving a blood sample over the next four weeks.
The blood will be processed to avoid contamination.
Patients will be monitored for five years and their brain volume, blood flow and disease markers will be measured. The results will be compared with a placebo group given saline transfusions.
Commenting on the trial, James Rowe, a professor of cognitive neurology at the University of Cambridge, said: "It is a very interesting idea. It may raise eyebrows, but there is serious science here, and we know that taking exercise lowers risk.
"We await the results with interest, and in the meantime, those of us who can, should be taking more exercise because we know it is one way we can all reduce the risk."
